The structures of four isomers are shown - HSC - SSCE Chemistry - Question 7 - 2020 - Paper 1

To determine which statement is correct, we first need to analyze the structures of the compounds in question.

1. Identifying Chain Isomers: Chain isomers are compounds with the same molecular formula but different arrangements of the carbon skeleton.

   • Compounds 1 and 2: Both compounds have the same carbon chain but differ in functional group positions, hence they are not chain isomers.
   • Compounds 1 and 4: Also feature different arrangements leading to different functional groups and structures, indicating they are not chain isomers.

2. Identifying Functional Group Isomers: Functional group isomers have the same molecular formula but different functional groups.

   • Compounds 2 and 3: These compounds feature different functional groups—alcohol versus ether. Therefore, they are classified as functional group isomers.

3. Identifying Positional Isomers: Positional isomers occur when the same functional group is attached to different carbon atoms.

   • Compounds 2 and 4: Both contain the same functional groups but in different positions on the carbon chain, classifying them as positional isomers.

Based on this analysis, the correct statement is: C. Compounds 2 and 3 are functional group isomers.